A gas diffusion electrode base material installed in a fuel cell is conventionally a porous electrode base material composed of a paper-like carbon/carbon composite which is obtained by sheet making of short carbon fibers for increasing mechanical strength, binding short carbon fibers with a thermosetting resin, and carbonizing an organic polymer with calcining at a high temperature (see, Patent Document 1).
Further, a porous electrode base material having carbon fibers and carbonaceous powder bound to each other with a resin carbide for enhancing the conductivity or mechanical strength in the thickness direction is suggested (see, Patent Document 2).